Matt Cassel knows a thing or two about replacing a legend.

The former New England Patriots quarterback, now with the Tennessee Titans, took over when Tom Brady suffered a season-ending knee injury in 2008. Cassel guided the Patriots to an 11-5 record, and thinks Jimmy Garoppolo will be just fine in his four-game stint to start the 2016 season.

“I don’t know if I’d give him any advice, as much as I’d tell him to go and take advantage of an opportunity,” Cassel said Friday. “He’s going into year three, so he’s been there. He knows the system. I’m sure they have a lot of confidence in him, otherwise he wouldn’t be there. And they have a great coaching staff who will have him well prepared. They’ll have a game plan ready for what he does well. I’m sure he’ll have a lot of confidence going into those games. He’s a talented kid. I’ve seen him play. I’m sure he’ll do a fantastic job.”

Unlike Garoppolo, who has a full training camp to prepare, Cassel was thrust into service after Brady tore up his left knee in the season opener. Cassel described the transition as a process, with the coaching staff gradually working him into the offense Brady manned with Randy Moss and Wes Welker.

There were subtle changes, and he expects they’ll do the same for Garoppolo.

“The offense definitely evolved as we went on, and the coaches started to have more confidence in my ability to manage and handle the offense. I was there for four years, but didn’t have a tremendous amount of playing time,” Cassel said. “It was one of those things they had to feel out those first few weeks with Tom being gone. And as we started to move forward, we got more comfortable opening up the entire offense. They thought I could handle more and I felt more confident as we moved forward. I think the coaches did a great job and it started to become the Patriots offense that we were used to seeing the entire time we were there.”

Patriots quarterback Jimmy Garoppolo tries to keep cool during practice Friday. Garoppolo is preparing to be the starter for the first four games of the season while Tom Brady serves a suspension.

Patriots quarterback Jimmy Garoppolo tries to keep cool during practice Friday. Garoppolo is preparing to be the starter for the first four games of the season while Tom Brady serves a suspension. Associated Press/Michael Dwyer

Cassel said Garoppolo needs to gain the trust of veterans like Julian Edelman and Rob Gronkowski.

“I had relationships with everybody, but at the same time, I still had to earn their trust, earn their respect,” he said. “You have to be out there competing, especially as a quarterback, you can understand the offense, you can call the plays in the huddle, you can get in and out of the huddle, and do all those little intangible things people don’t talk about. It’s not just playing the game, but it’s giving guys confidence as you break the huddle going to the line of scrimmage. I think that takes time. The only way you earn that, is going out there and performing.”

Remembering 2008, Cassel praised Bill Belichick and the staff, a great support system of veteran players and, naturally, Brady.

“Tom was an ear any time I needed it,” Cassel said. “He was a guy I could call at any moment, and he was the first guy to wish me luck before a game, and the first guy to call me after a game and give me encouragement. So all those things were huge for me.”

And Cassel doesn’t like that his friend Brady has to sit those four games over Deflategate.

“No, I’m not a big fan of (the punishment) at all. I think it’s a tough situation. I played with Tom. I have the utmost respect for him as a person, and also I know Tommy really well. He’s a honest guy. He’s done everything right.

“Unfortunately, this situation came about, and it turned out to be what it is. But at the same time, I don’t necessarily agree with it.”

TEXANS: Star wide receiver DeAndre Hopkins did not report for the first day of training camp.

Entering his fourth pro season, Hopkins is holding out for a new contract. He is scheduled to make $1 million in the final season of his rookie contract, though the Texans have picked up his fifth-year option.

Hopkins can be fined up to $40,000 for every day he misses camp.

He’s coming off a huge season with 111 receptions, 1,521 yards receiving and 11 touchdowns despite inconsistency at quarterback and few other receiving options on the Texans.

VIKINGS: Minnesota is keeping kickoff returner/wide receiver Cordarrelle Patterson out of practice, following an injury around his left shoulder.

Patterson fell hard on his shoulder Friday while trying to make a catch. He was in immediate discomfort but appeared to be in good spirits later.

Running back Adrian Peterson has been held out of full-team drills at the start of training camp. Coach Mike Zimmer said Peterson has a minor injury from offseason training.

Offensive lineman Mike Harris is dealing with an undisclosed illness that’s keeping him out of practice. He said he hopes to be able to return soon but wasn’t sure if he’d be on the field this season.

49ERS: Right tackle Anthony Davis was reinstated by the NFL after an 11-month retirement that he planned to come back from all along.

Davis was the 49ers’ first-round draft choice, the 11th overall pick, in the 2010 draft out of Rutgers. He was affected by a concussion late in the 2014 season and announced his retirement last June. He became the fourth prominent San Francisco player to retire in a three-month span, joining linebackers Patrick Willis and Chris Borland and defensive end Justin Smith.

CHIEFS: Kansas City signed left tackle Eric Fisher to a contract extension.

The Chiefs didn’t announce terms of the extension, but a person familiar with the negotiations told the Associated Press it was a four-year, $48 million deal that includes $40 million guaranteed. The person spoke on condition of anonymity because the contract terms were confidential.

BEARS: Chicago signed outside linebacker Willie Young to a two-year contract extension.

Financial terms of the contract were not disclosed.

Young, 30, signed with the Bears two years ago after spending his first four seasons with division-rival Detroit. He had a career-high 10 sacks that year before tearing his Achilles tendon in December, but bounced back to play in 15 games with 61/2 sacks last season.

FALCONS: Julio Jones insists the apparent foot injury that has limited him the first three days of training camp is no big deal.

Jones took part in individual work but was held out of team drills for the second straight day.